This invention relates to fetal probes and, more particularly to a connector assembly for coupling a fetal electrode to a remote monitoring device.
One type of fetal probe comprises a bipolar fetal electrode commonly used to monitor fetal heart rate during birth. This type of probe consists of a spiral fetal electrode mounted on a carrier along with an electrically isolated maternal electrode. A twisted pair of wires are connected at one end to the fetal and maternal electrodes and at their opposite ends to a connector. One such connector consists of a pair of axially spaced electrodes which are electrically isolated and each of which is connected to one of the wires. The connector is adapted to be coupled to a socket having axially spaced connectors which, in turn, are coupled by a cable to the monitor.
Initially, the twisted pair of conductors and the connector are disposed in a hollow drive tube. The end of the drive tube is inserted into the mother's cervix until the forward end contacts the fetus. The role of the drive tube is to push forwardly until the spiral fetal electrode at the forward end makes contact with the fetal epidermis. The drive tube is then rotated to screw the spiral electrode into the fetal epidermis. The drive tube is then slid over the wires and the connector while the bipolar electrodes and the twisted pair of wires remain within the mother and connected to the fetus. The removal of prior art tubes required the dexterous manipulation of the drive tube which were designed to maintain a grip on the twisted pair so as to insure that the drive tube is engaged at the distal end. Defeating the grip tended to be cumbersome. In these prior art connectors, the connector at the other end of the twisted pair of conductors is exposed. Such exposed electrodes could soil or contact energy sources and tended to be disconcerting to the patient or her partner.
In one type of assembly the socket for receiving the connector is mounted on a support or circuit board which electrically connects to a plate mounted on the mother's leg by an adhesive pad and provides a reference for the fetal and maternal electrodes. The support or circuit board connects to the leg plate by a snap electrical connector. Such snap connectors do not uniformly provide a distinct snap to indicate that good electrical contact has been achieved. In addition, the forces necessary to couple and disconnect the contacts are not consistent. As a result, medical personnel may not be aware should a good electrical connection not be achieved.